Two special issues in merchandise planning and management are disruptive events and replacement or substitution of items. Disruptive events change the pattern of sales for a good. Many disruptive events can be represented by a step function. That is, sales will step up or down at a relatively well-defined point in time and remain impacted. Disruptive events may impact needs for and sales of items either negatively or positively. For instance, introduction of a large package size of a good can negatively impact sales of small packages of the same good. The large package size cannibalizes sales of the small packages. Introduction of a complementary good, for instance, introducing jelly at a store that sells bread and peanut butter, could have a positive impact on sales of the related good. Competition, both from competitors' stores and sister stores, has similar step function impacts. Opening of a new store nearby can decrease sales. Closing of a nearby store can increase sales. Opening of complementary stores can increase neighborhood sales traffic and have a positive impact on sales. Disruptive events can impact items, locations or item/location pairs.
Replacement of items involves feathering together old and new items or treating them as if they were different items. The feathering of the old and the new item typically involves the old item remaining on the shelf side by side with the new item until the old item is sold out. In the feathering case introduction of a replacement item is not as simple as copying old item information to the new item and building upon it. A system maintains many types of old item-related information, some of which are not subject to bulk transfer in the feathering case. It may also be desirable to jointly manage the phase out of the old item inventory while phasing in the new item inventory in a way that the stocking of the new item is affected by the remaining stock of the old item. A system also may need to segregate inventory and sales of the old and new items for one reason or another. At the same time, it may be desirable to treat the old and new items as one for most reporting purposes, taking care not to double count the old items for themselves and as items new items.
An opportunity arises for careful handling of disruptive events and replacement items, in order to enhance the effectiveness of merchandise planning and management systems, preferably with a modest input effort from operating personnel.